Kurai

Results 3 issues of Kurai

It would be great if you added support for TypeScript users EDIT: I didn't realized there was a [`types`](https://github.com/xtuc/webassemblyjs/tree/master/types) directory. Consider renaming the files from `*.js` to `*.d.ts`?

Add support for TypeScript users.You don't have to rewrite everything. A `.d.ts` file is enough. If you want, I can submit a PR. Thanks in advance.